Systemic lupus erythematosus (SLE) is a protean disease of unknown etiology which affects multiple organs. Lahita, R. G. Systemic Lupus Erythematosus, Churchill, Livingston, N.Y. (1987) page XXIX. Although there is a marked similarity to an infectious entity, an exhaustive search for an etiologic agent has not yielded any proven candidates that fulfill the criteria for causation of this disease. Crow et al., "Etiologic Hypothesis for Systemic Lupus Erythematosus," in Lahita Systemic Lupus Erythematosus, Churchill, Livingston, N.Y. (1987) page 51 ff. There is general agreement that tissue and organ injury in SLE is mediated by immune phenomena. Unexplained at this time is the predilection of SLE for females. Taurog et al., Intern. J. Derm., 20:149-158 (1981).
Early descriptions of SLE before the advent of suppressive therapy suggested sepsis, and included fever, striking constitutional symptoms and high mortality. Crow et al., "Etiologic Hypothesis for Systemic Lupus Erythematosus," in Lahita Systemic Lupus Erythematosus, Churchill, Livingston, N.Y. (1987) page 54. Recently, many viral etiologic agents have been sought; none have been convincingly demonstrated. Pincus, Arthr & Rheum, 20:149-158 (1982). More recently the characterization of soluble products of bacteria and mycoplasmas with unique capacities to perturb immune systems have led to new considerations in regard to the infectious trigger of SLE.
Intra-erythrocyte organisms with characteristics like the Anaplasmataceae that were thought to be Haemobartonella-like were first suggested as exciting exogenous agents in SLE by Kallick et al., Nature New Biology, 236:145-146 (1972). The Anaplasmataceae family of bacteria are Proteobacteria of the order Rickettsiales. That report was further developed by a later report of antigenic similarities between SLE or lupus nephritis and diseases caused by Anaplasma marginale, an intra-erythrocytic parasite of cattle, and a member of the family Anaplasmataceae. Kallick et al., Arthr. Rheum., 23:197-205 (1980).
Exogenous intra-erythrocytic structures seen in the same erythrocyte by giemsa staining and phase contrast microscopy, which were identical or very similar in appearance to Anaplasma marginale, have been observed in most patients with SLE. However, because the number of such structures seen in erythrocytes of SLE patients is very small, their presence has been unconfirmed by electron microscopy, until the present study. For example, the number of infected erythrocytes is usually less than 0.1 percent of observed erythrocytes in fixed thin blood films.
Based upon available data, which describe the pathology of SLE as tissue destruction associated with antibody formation and the development of antibodies against many body tissues as well as pathogens such as Epstein-Barr virus, and assuming that Anaplasmataceae or similar intra-erythrocytic pathogens are present in an uncontrolled parasitemia in SLE, a pathological mechanism can be deduced that contains, at least in part, a continued antigenic stimulation of the B-cell immune mechanism. The Anaplasmataceae were thought to offer an ideal putative model of infection, in that, based on studies by the inventor, above, they present an approximately 1 percent parasitemia or less level in systemic lupus erythematosus patients.
The Anaplasmataceae have been extensively studied in animals, and although they affect erythrocytes as a primary organ, their pathogenic potential appears to be primarily or exclusively mediated by immune mechanisms primarily identified as humoral. Immunity to Blood parasites in Animals and Man, Miller et al. eds., Plenum Press, New York (1977) pages 155-188. In animal disease, antibiotics control the primary pathologic event, hemolytic anemia, only if given early in the course of the illness. Late in the course of animal illness the hemolytic anemia is mediated by antibody formation and antibiotics do not appear to affect the course of the usually studied hemolytic anemia.
In animals, arthritis and long-term effects of illness after infection have not been studied or reported. However, in some animals that suffer hemolytic anemia such as adult bulls, chronic arthritis and anemia have been reported. In the veterinary literature, an antibiotic that appears to suppress some of the clinical manifestations of these organisms is tetracycline or one of its analogues. Franklin et al., Southwestern Vet., 15:131-139 (1962).
Several humans with SLE or connective tissue disease have been treated with tetracycline (doxycycline) in preliminary work of the inventor based on the presumption of Anaplasmataceae parasitemia. Three patients are exemplary.
The first was a 17 year old female with severe SLE and nephritis who experienced a lysis of fever within a week of therapy with disappearance of Haemobartonella-like agents from the circulating erythrocytes as observed by acridine orange and fluorescent antibody determination. This patient was not subsequently followed.
The second patient is a male with SLE who has been taking tetracycline for his lupus for 10 years. He stated that his fever, joint pains, and other symptoms disappeared while he was taking tetracycline. He had first been given the antibiotic for treatment of another infection and noted it caused amelioration of his SLE.
The third is a patient who has mixed connective tissue disorder resembling SLE but with a negative ANA titer. This patient went into remission of her symptomatology after 3 weeks of therapy with tetracycline and has remained in clinical remission for the subsequent 3 months. It is of interest that in addition to marked subjective improvement of this last patient, C-reactive protein became negative after tetracycline therapy was begun.
Subsequent to these studied patients, a large number of other patients with SLE have received chronic therapy with tetracycline or its derivatives. These treatments have been on a compassionate basis by the patients' own physicians, or as part of a study approved by an institutional review board, but not completed. Most of such treatments have resulted in amelioration of the disease state, with complete remission, or a trend in such amelioration. That study, done at Cook County Hospital, Chicago, Ill., was terminated before the results, as analyzed, were shown to be statistically significant. The results appeared to be based on the small numbers analyzed.
A current patient studied is a splenectomized female with SLE who had a large number of parasitized erythrocytes beginning with about 16 percent. She has been on doxycycline with informed consent for 16 months with initial and continued improvement. Because she has enough intra-erythrocytic parasites to be counted, her course of treatment has been followed and electron microscopy was carried out. When examined in December 1995, she still had about 1.1 percent parasitized erythrocytes seen by giemsa staining and phase contrast microscopy.
Aureomycin, a tetracycline-like drug, has been proposed as a treatment for rheumatoid diseases in the past by T. Brown and co-workers and others, who treated a variety of patients with arthritis and lupus with claims of some degree of success in the 1940's. [Brown et al., J. Lab. Clin. Med., 34:1404-1410 (1949); Scheff et al., Infec. Dis., 98:113 (1956)] Those studies were not controlled, and have not been repeated. These theoretical and observed phenomena suggest that tetracycline may be of benefit in the syndrome of SLE.
Present therapy of SLE is based upon heavy steroid use with immunosuppressives and/or plasmapheresis. It is of interest that Anaplasmataceae infections in animals are, almost uniquely among infectious diseases, ameliorated by steroids.[Scheff et al., Infec. Dis., 98:113 (1956); Ristic et al., J. Vet. Res., 19:37 (1958)]
No presently used therapy is completely satisfactory, and, although the life expectancy of lupus patients has been considerably increased by present therapy, the ravages of therapeutic side effects and the constant fatigue takes a severe toll in well being, general health, and increased morbidity and mortality of the estimated 500,000 Americans with this disease. Dubois, Lupus Erythematosus, 2d ed., U.S. California Press, Los Angeles (1974).
The spleen is regulatory in removing nuclear remnants and other intra-erythrocytic particles from erythrocytes, and in Anaplasmosis as well as malaria, splenectomy causes a recrudescence of clinical disease and parasitemia. Kreier, Ann. Rev. Microbiol., 325-38 (1981). Splenectomy is an infrequently used treatment for the thrombocytopenia seen in some patients with SLE. Coon, So. Amer. J. Surgery, 155:391 (1988). However, the one splenectomy patient noted before was found to have parasitemias of erythrocytes with intra-erythrocytic phase contrast-visible refractile bodies in up to about 16 percent of her studied erythrocytes (FIGS. 1 and 2). These intra-erythrocytic bodies were very similar or identical to those seen in bovine A. marginale infection.
It would therefore be beneficial if the stainable exogenous structures found in the erythrocytes of SLE patients could be accurately identified, readily assayed for and eliminated from a patient's blood in that it is believed that those exogenous structures are the active, causative agent for SLE. The description that follows describes a treatment regimen that eliminates those exogenous bacterial structures from an SLE patient's blood.
In 1891 Howell described intra-erythrocytic bodies that occurred in splenectomized patients and animals. The appearance of these bodies that now bear the name Howell-Jolly bodies followed within a few hours or days of splenectomy. The elegant drawings of Dr. Howell, whose findings have been subsequently confirmed by others with modern methods including electron microscopy, have amptly demonstrated this phenomenon. The spleen in the normal patient removes the few nuclear remnants that are not absorbed or extruded in the bone marrow.
Howell-Jolly bodies are described as about 1 .mu. in diameter in an eccentric position in the erythrocyte. The bodies seen in anaplasmosis and in the patients with SLE are approximately 0.5 .mu. and have phase refractile characteristics that are not described in Howell-Jolly bodies. It is believed that the site of generation of the agents seen in SLE patients'erythrocytes is in the normoblasts or other cells of the bone marrow. These agents are normally removed by the spleen, but in the splenectomized patient are constantly circulating until the erythrocyte is senescent and destroyed in the reticulo-endothelial system. These particles in the normoblasts appear to have heretofore escaped detection because they morphologically resemble the normal metamorphosis of the normoblast, but are smaller.